Ceramic composites are known in the art. Uses of certain known ceramic composites include abrasive articles (e.g., abrasive wheels and honing sticks), cutting tools, and cutting tool inserts.
For many uses of composite materials (e.g., abrasive wheels and honing sticks), cutting tools, and cutting tool inserts, it is generally desirable that the interface between the matrix and the dispersed phase maintain its desired properties (e.g., strength and integrity) throughout the temperature ranges encountered during use. For example, it is desirable that the matrix and the dispersed phases have similar thermal expansion coefficients so as to minimize thermal stresses at the interface and consequently maintain the integrity of the interface. Furthermore, in many applications it is desirable to have the matrix and the dispersed phase form a strong interface. Typically, some limited reaction at the interface promotes a stronger bond but, extensive reactivity between the components tends to lead to deterioration of the desired properties of either or both phase(s). Hence, obtaining desirable thermal, chemical and mechanical properties of the interfaces is useful for composite articles.
Designing ceramic composites including articles (e.g., abrasive wheels and honing sticks), cutting tools, and cutting tool inserts traditionally involves trying to develop matrix phases (typically silica-based glasses) that match the thermal expansion coefficient of a ceramic abrasive grain, and at the same time form a strong interface, by controlling the chemical composition of the bond (i.e., the matrix) and the abrasive grain (i.e., the dispersed phase) and firing conditions (e.g., time, temperature, heating and cooling rate, etc.) of the composite article. However, many of the chemical components added to the silica-based matrix (e.g., alkali metal, alkaline earth metal and boron oxides), react detrimentally with the abrasive grains. Such reactions are more problematic with crystalline ceramics that have sub-micron crystal sizes. When the firing temperature or firing time are reduced to avoid such reactions, the strength of the matix-dipersed phase interface and consequently the whole composite article tends to be reduced.
The ceramic composite, abrasive, and cutting tool industries continue to desire new materials, abrasive articles, cutting tools, and cutting tool inserts, as well as methods for making the same.